Originally Posted by Ken H
Perhaps you should reserve judgement until you've heard it. I have, and it's an improvement over the same content in standard 48 kHz.
Is it an objective improvement or a euphonic effect?
Also, how does one remove artifacts that were caused by the A-to-D process, as the Dolby press material claims to do? Specifically, if the A-to-D process sampled at 48 kHz, there always has to be a brickwall filter with a stopband at 24 kHz. How do you undo that?
Originally Posted by Roger Dressler
Here's an AES paper
describing the science and engineering.Here's
Both papers work out the math very well, but neither really speak to the audibility or the audible effects of such filters. The Dunn paper conjectures on it, but it's really about the math of the process.
Let me ask a basic question: at what frequency is the pre-ringing occurring? The Dolby press material shows two graphs, one with pre-ringing, and one without, but the X-axis has no units, so one cannot work out the frequency of the ringing.
Assuming you have the answer to the first question, consider a second question: if the frequency of the ringing is above human audibility (say >20kHz), is it still important?
Consider a third question: if in order to create an impulse response with no preringing, one must create a phase shift (and the math shows that one must), then when is that phase shift audible, and what are its effects?
Some people have tried to answer those questions, and the answers were, to me, surprising.